1. FIELD OF THE INVENTION
The invention relates to a railway level crossing, i.e. a crossing where road and rail are at the same level. This is also known as a grade crossing.
2. DESCRIPTION OF THE PRIOR ART
According to a press report, a new method has been adopted, initially in Recklinghausen, by the German Federal Railway in concert with Chemische Werke Huls AG and Gummiwerk Kraiburg, for the completion of much frequented railway level crossings, by replacing the hitherto usual road surface of asphalt, concrete plates or pavement by pre-shaped plates of a thickness of 193 mm and made of synthetic ethylene-propylene rubber. This material ("Allwetterkautschuk Buna AP") is highly resistant to ozone, ultraviolet light and other atmospheric effects. At raised temperatures it also displays good resistance to ageing, that is to say has no tendency to become brittle or to formation of cracks. The danger of road vehicles skidding in wet weather is prevented by the special profiling of the surface. The plates are provided with accurately profiled recesses for the sides of the rails and for fastening them to the rails, so that a fixed connection is assured. In addition to the technical advantages of considerably reducing assembly time and better resistance to road traffic, this new development is distinguished by a substantial reduction in the noise level of the road traffic crossing the rails.
Another known level crossing design, described in the leaflet "Rubber level crossings" of Trelleborgs Gummifabriks AB, is also based on a special rubber plate lying on a bed of joined-together wooden longitudinal beams, and completely covering this bed. The edges of the plates lying between the rails are provided with deep pre-shaped channels for the wheel flanges of a train. The lip of the channel directed upwards under the rail head is pressed against the underside of the rail head, so that the rubber plate is kept in its place on the wooden bed without the use of nails, bolts or adhesives. At the same time this results in effective sealing against dirt which might penetrate into the ballast bed. One of the advantages mentioned for such a level crossing is easier cleaning. On level crossings in industrial areas the channel need only be cleaned once in a while. Because of the elasticity of the rubber, removal of ice is also no longer a problem. Clamps screwed onto the ends of the bed of beams prevent the plates from shifting in the longitudinal direction.
U.S.A. Pat. No. 3,465,963 shows a level crossing in which the gap between a reinforced rubber plate and the rail is filled by an elastomeric strip. This strip has cavities in its underside enabling it to be resiliently deformed by the flange of a passing wheel.
U.S.A. Pat. No. 3,469,783 shows a level crossing wherein gaps between a concrete bed and the rails are filled by a cushioning member having internal cavities to allow it to be resiliently deformed by a passing flange.